If you watch the video very carefully you can see that while Ike is keeping his guard up he's constantly motioning with both hands. Yes he does do a little bit of a fist pump before throwing his jab, but he's moving both hands very subtly and throwing feints with those fist pumps that he doesn't follow immediately with the jab. He also makes a very similar motion prior to throwing his hook so the standard slip to the outside defense could lead to you eating a left hook. The same goes for preparing to parry the jab with the right hand and the hook comes instead. This is one of the primary reasons using feints are absolutely neccessary. They've become a lost art for the most part except for the very best in the boxing game and are nearly impossible to find in MMA.